Cased Axial Fans

Cased axial fans sit inside a cylindrical case with flanged connections at both ends, so they install inline on ductwork rather than through a wall. That case is what lets them work against higher static pressure than a plate axial and take accessories like silencers, guards and flexible connectors. eFans stocks 129 cased axial fans from 200mm to 1000mm: Systemair AR Sileo, Elta SCD and SLC Revolution long cased, Elta Raptor SDA, S&P TCBB and Vent-Axia ESC.

Short cased suits general extract and supply on straightforward duct runs. Long cased handles longer runs, higher resistance and anywhere the duty point sits further up the curve. Motor options are single-phase AC (230V), three-phase AC (400V) and EC, all speed controllable. UK stock, next-day delivery, trade accounts available. Email hello@efans.co.uk or call 0161 399 3825 for quotes or sizing help.

All Axial Fans / Plate Axial Fans / Duct Mounted Axial Fans / Roof Fans / Ducting Silencers / Speed Controllers

Cased axial fan or plate axial fan?

A cased axial fan is installed inline on ductwork, with the case forming part of the duct run. A plate axial fan is mounted on a flat plate and fixed through an external wall or bulkhead, with no duct housing around it. Specify cased where the scheme is ducted, where there are multiple grilles or zones, or where the system resistance is high enough that a plate axial would lose too much airflow. Specify plate for direct through-wall extract on short or absent duct runs. See plate axial fans.

Short cased or long cased?

Short cased axial fans have a case roughly as deep as the motor and impeller, and suit general extract and supply where the duct run is straightforward. Long cased fans use an extended case that improves the airflow profile and lets the fan work against higher pressure, and they give you the length to fit guards, silencers and flexible connectors within the same run. The Elta SLC Revolution range is the long cased option we stock most of. If the system has filters, silencers, long duct runs or several bends, price the long cased version before defaulting to short.

Applications of cased axial fans

Cased axial fans are used for ducted ventilation in industrial, commercial and larger residential settings: workshops, factories, warehouses, commercial kitchens, car parks, plant rooms and HVAC systems where airflow has to be routed rather than simply pushed through a wall. The cased design handles higher-pressure environments, integrates directly with rigid or flexible ducting, and protects the impeller from external debris and damage.

How to choose the right cased axial fan

Size from the airflow you need (m³/h) and the resistance the system puts in the way, not from the free-air figure on the datasheet. Duct length, diameter, bends, grilles, louvres, filters and silencers all add static pressure, and an axial fan loses airflow steeply as pressure rises. Then check the duct diameter you are connecting to, the supply available at the fan position (single or three-phase), the noise limit for the space, and the IP rating if there is moisture or dust. Where the calculation is marginal, size up and run the fan through a speed controller.

Installation and positioning

Cased axial fans mount inline on the duct, on a wall, ceiling or within a plant room run. Support the fan independently rather than hanging it off the ductwork, use flexible connectors either side to stop vibration carrying into the duct, and leave clearance for maintenance access. Keep straight duct either side of the fan where you can, since bends immediately at the inlet or discharge cost airflow and add noise. Correct installation protects performance and extends the life of the unit.

How noisy are cased axial fans?

Noise depends on size, duty and motor, but a cased unit is usually quieter than an open fan because the case reduces turbulence and vibration. The biggest single lever is running a larger fan at reduced speed rather than a smaller fan at full duty. Where the space is noise-sensitive, specify a Sileo or acoustically rated model and add a duct silencer on the discharge.

Can cased axial fans be used outdoors?

Many can. Check the IP rating and casing material on the product datasheet before specifying for an outdoor or semi-exposed position, and protect the motor terminal box from direct weather. For a fully external roof-level duty, a purpose-built roof fan is usually the better answer.

Can cased axial fans handle high temperatures or humidity?

Yes, if specified with suitable motor insulation and casing materials. Confirm the thermal and IP ratings meet the duty before ordering. For sustained hot air streams see our high temperature fans, and for hot or contaminated air where the motor must stay out of the airstream a bifurcated fan is the correct design.

Are replacement parts available?

Yes. Most commercial cased axial fans have replaceable motors, bearings and impellers. Using OEM parts maintains performance and efficiency, which matters most on units running continuously. Send us the model code and we will confirm what is available.

Can multiple cased axial fans be used in one system?

Yes. Fans can be combined in a ducted system to increase airflow, provide redundancy, or serve separate zones. Fans in parallel add airflow; fans in series add pressure. Both need the system balanced properly and the controls planned, so send us the layout and we will check it before you order.

Do you do trade pricing on cased axial fans?

Yes. eFans supplies M&E contractors, ventilation installers, facilities teams and maintenance contractors across the UK, with trade accounts and net payment terms for regular buyers. Send your schedule, drawing or brief and we will size the scheme, quote matched fans, silencers and controls, and arrange next-day or scheduled site delivery. Contact hello@efans.co.uk or call 0161 399 3825.